1. Technical Field
The present invention pertains to a method for selecting progressive ophthalmic lenses for a given frame fitted to a determined wearer.
2. Related Art
Progressive ophthalmic lenses are associated with a medical prescription and they are housed in a frame that the wearer chooses as a function of his tastes.
Lenses of this type exhibit a far vision zone, situated in the upper part of the lens and a near vision zone situated in the lower part. These vision zones exhibit different optical characteristics. Hence, and this is a particular feature of this type of ophthalmic lens, it exhibits a progression corridor which extends from one zone to the other, and whose optical characteristics vary in a continuous manner. Thus, from the far vision zone to the near vision zone, the optical characteristics of the far vision zone evolve progressively to the optical characteristics of the near vision zone. This allows the wearer to pass from one zone to the other without inconvenience and with a certain comfort.
However, this progression corridor and especially its length may vary from one frame to another. It is indeed understood that the progression length varies as a function of the position of the ophthalmic lenses with respect to the eye, and consequently with respect to the chosen frame.
Hence, it has been contemplated to take into account the size and the shape of the frame for the purposes of optimizing the progressive ophthalmic lens is brought to an optimal level of comfort for the wearer. It will be possible especially to refer to the document FR 2 898 193, which describes a procedure for determining a progressive ophthalmic lens suited to the wearer and to the chosen frame.
The procedure calls upon representative parameters obtained on the basis of mean values which are themselves calculated on the basis of a given population sample. Despite these precautions, it turns out that certain people experience difficulties in enduring their progressive ophthalmic lenses.
Hence, a problem which arises and which the present invention is intended to solve is to provide a method for selecting progressive ophthalmic lenses as a function of the characteristics of the wearer and of the frame that he chooses, so as to yet further increase his comfort of vision.